JP2731032B2 - Methods for detecting and treating malignant and non-malignant lesions by photochemotherapy - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to the detection and treatment of certain tissue abnormalities (both cancerous and non-malignant) by inductive fluorescence and photochemotherapy, respectively.

BACKGROUND OF THE INVENTION Tissue abnormalities that usually affect the skin are detected and evaluated by a combination of visual inspection and palpation. In some clinical situations, non-white light (narrow band in ultraviolet or visible)
The sensitivity of the visual inspection can be increased by the use of or by the pre-application of a contrast-enhancing agent such as dilute acetic acid or certain dyes. Tissue abnormalities including non-palpable surfaces (eg, bronchi or bladder) can be visualized with a suitable scope. Some special scopes can detect induced fluorescence. If the abnormality in question is related to any difference in the extent or pattern of tissue angiogenesis, such a scope would be used when passing it through the vasculature of both diseased and neighboring normal tissue. By visualizing the injected fluorescent agent, the limits of the region involved in the abnormality can be determined.

In addition, the fluorescence detection scope includes exogenous porphyrin,
For example, it has been used experimentally to identify areas of tissue that show strong porphyrin fluorescence after intravenous injection of hematoporphyrin IX (Hp IX), hematoporphyrin derivative (HpD) or “dihematoporphyrin ether” (Photofrin II). ing. Although such porphyrins tend to accumulate semi-predominantly in malignant tissues, they also accumulate in tissues that are regenerating after injury or in rapidly growing tissues of embryos or fetuses. Normal liver, spleen and kidney also tend to accumulate their porphyrins. Using such compounds and a fluorescence detection scope, areas of malignant tissue that are too small to be identified by standard format visual inspection have been identified in the bronchi and bladder.

Cells and tissues in which porphyrins accumulate semiselectively are referred to as "cells in which porphyrins accumulate semiselectively".
Such cell properties have been reported in the literature, as exhibiting strong porphyrin fluorescence following intravenous injection of endogenous porphyrin, or as being determinable experimentally by known methods.

Unfortunately, a clinically significant (photosensitized) amount of porphyrin persists in the skin for at least two weeks (sometimes more than two months) after intravenous injection of Hp IX, HpD or Photofrin II. This means that patients must avoid exposure to sunlight (direct or through glazing) for long periods after injection. As you can see,
Patient compliance is often poor, and accidental phototoxic "tanning" generally occurs several weeks after the diagnosis or therapeutic injection of porphyrins. Persistent photosensitization is a major hazard associated with this method, and is why it is not so widely used.

The standard or conventional forms of treatment for cancer are surgery, radiation therapy and chemotherapy. However, other treatment modalities are known, including photochemotherapy or photodynamic therapy (PDT). Based on experience, PDT is currently used to treat several different types of cancer as well as certain non-malignant lesions such as psoriasis. The patient is administered a photoactivated reagent having some specificity for the tissue to be treated. The tissue area containing the target tissue is then exposed to light-activated light that destroys the target tissue but causes only mild and reversible damage to other tissues in the same treatment area.

Currently, there are two main types of photochemotherapeutic drugs for clinical use. The first type, methoxypsoralen, is administered systemically. Ultraviolet light is essential to activate them. Local exposure of psoralen-containing tissues to ultraviolet light induces a local photochemical reaction that covalently binds the drug to the DNA of living cells and destroys their proliferative power. The second type, porphyrins, are administered systemically (by intravenous injection), but sometimes are administered either locally or by intralesional injection. They can be activated by visible (red) light. Such local exposure of porphyrin-containing tissue to light does not induce a chemical reaction between cellular components and porphyrin molecules. Instead, porphyrins act as catalysts by trapping the energy of photoactivated light and then passing it on to molecular oxygen, which then puts it into an excited state that can oxidize nearby molecules or structures. Cell death is not primarily caused by DNA damage, but rather by damage to the intrinsic membrane structure.

Photochemotherapy is currently used to treat non-malignant lesions, including certain types of cancer and psoriasis. The goal of such therapy is sometimes treatment (primarily for basal cell carcinoma), but usually, when it appears that the standard form of therapy will probably have a significant degree of effect on patients, the goal is Relief by local control.

Methoxypsoralen (PUVA) therapy is used primarily to treat psoriasis, but is sometimes used to treat very superficial cancers that affect the skin (primarily mushroom fungi). However, there are two serious problems with such treatment. First, the method has been proven to be carcinogenic in humans. Second, the depth at which the malignant tissue can be killed is limited to a few millimeters below the illuminated surface, since the photoactivating light is very strongly absorbed by most tissues. These problems severely limit the usefulness of methoxypsoralen for photochemotherapy.

Currently, the most commonly used porphyrins for photochemotherapy are hematoporphyrin IX (Hp IX), hematoporphyrin derivatives (HpD), and Photofrin II, a semi-purified form of HpD. When porphyrins are used as photosensitizers, cell death results from damage to the intrinsic membrane structure rather than to DNA. Thus, malignant transformation is not a serious problem. In addition, the visible (red) light used to photoactivate porphyrins is
Because it penetrates tissue much deeper than the UV light used to photoactivate methoxypsoralen, the depth at which porphyrin-treated tissue can be killed is significantly greater. Also, because certain types of porphyrins show a significant tendency to accumulate predominantly in malignant tissue, it is sometimes possible to destroy malignant tissue without causing clinically significant damage to nearby normal tissue.

A major problem with systemic application of Hp IX, HpD and Photofrin II is that photosensitizing concentrations persist in the skin for weeks to months after their administration. As a result, severe accidental phototoxic skin reactions can occur unless the patient avoids sunlight (direct or through window glass) until the concentration of photosensitizer in the skin has decreased to harmless levels. Current,
The problem of photosensitization after administration of porphyrins is to avoid any form of exposure to sunlight (or to very bright artificial light) for at least two weeks after injection, and then to be very careful with exposure to sunlight Is being treated by advising you to start. It is quite inconvenient to do this, so not all patients will follow their teachings. In addition, the use of sunscreens with high light blocking power is suggested with a warning that it only reduces some danger and does not completely eliminate it. In a few cases, patients who had been sensitized for more than one month after treatment were given high daily doses of β-carotene for several months in an attempt to prevent accidental phototoxic damage. Finally, attempts have been made to reduce phototoxicity by applying a photosensitizer locally to a limited area.

However, another topical problem is encountered when Hp IX or HpD is applied topically in DMSO (dimethyl sulfoxide) Azone, or some other excipient for the purpose of increasing tissue diffusion. After the DMSO Azone becomes diluted with normal tissue fluid to such an extent that porphyrin can no longer diffuse into tissue (or remain in solution), porphyrins tend to become immobilized where they occur. is there. As a result, topical application of porphyrins has been associated with reduced specificity for malignant tissue, and normal tissues near the site of application can generate sustained photosensitization from local enrichment of porphyrins.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a method for detecting certain types of malignant and non-malignant tissue by induced luminescence.

It is another object of the present invention to provide a system that can be administered either systemically or locally using an agent that is not a photosensitizer per se but induces the synthesis of protoporphyrin IX (Pp IX) in vivo. It is to provide a dynamic (photosensitizing) treatment method.

According to one aspect of the present invention, there is provided a method for detecting malignant and non-malignant lesions in a patient, wherein the protoporphin is in a heme biosynthetic pathway so as to induce the accumulation of protoporphyrin IX in said lesions. Administering to the patient an effective amount of a precursor of IX, and exposing the lesion to light having a wavelength within the absorption spectrum of the protoporphyrin IX, thereby inducing fluorescence in the lesion. It is to provide.

According to another aspect of the present invention, there is provided a method of treating malignant and non-malignant hyperproliferative hyperplasia of the skin, mucous membranes, endometrium and urothelium of a patient, comprising the synthesis of protoporphyrin IX in said lesion. Administering to the patient an effective amount of a precursor of protoporphyrin IX in the heme biosynthetic pathway, and exposing the lesion to light having a wavelength within the photoactivation spectrum of the Pp IX And thereby inducing fluorescence into said lesion.

In a preferred embodiment of the present invention, a preferred precursor of protoporphyrin IX is 5-amino-4-oxopentanoic acid, also known as 5-aminolevulinic acid, and the preferred wavelength of the photoactivating light is in the region of 350-635 nm. And more preferably about 635 nm red light.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Protoporphyrin IX, a naturally occurring photosensitizer
(Pp IX) is the immediate precursor of heme in the heme biosynthetic pathway. Since heme is required for the synthesis of various key heme-containing enzymes, all nucleated cells have at least a minimal ability to synthesize PpIX. Certain types of cells and tissues can synthesize relatively large amounts of PpIX.
Under normal conditions, the synthesis of Pp IX in such tissues is under strict feedback control such that cells produce Pp IX at a rate just enough to meet heme requirements. However, the normal rate-limiting step in this process, the synthesis of 5-aminolevulinic acid (ALA), involves exogenous A
It can be bypassed by the supply of LA, porphobilinogen or other Pp IX precursors. Certain tissues and organs have large excesses so that they are fluorescent and photosensitizing.
Will accumulate Pp IX. Pp IX, at least for skin
Appear to be synthesized on the fly. Sigma Chemical C
ALA, commercially available from ompany and water-soluble,
It can be administered orally, topically or by injection. The oral or parenteral route results in the induction of clinically useful concentrations of Pp IX into certain benign and malignant tissues throughout the body. Only certain types of tissue can synthesize clinically useful amounts of Pp IX when supplied with excess ALA, so that ALA is only produced when the affected tissue is at a site accessible to light-activated light. Supply is advantageous. At the moment, the skin,
Treatment of basal cell carcinoma, basal squamous cell carcinoma and squamous cell carcinoma of the mucosa (respiratory, gastrointestinal and vaginal), endometrium and urothelium and other lesions is expected.
The sites include (i) skin and conjunctiva; (ii) the lining of the mouth, pharynx, esophagus, stomach, intestine and intestinal appendages, rectum and anal canal; (iii) nasal passages, nasal cavity, nasopharynx, trachea, bronchi and (Iv) lining of the ureter, bladder and urethra; (v) lining of the vagina, cervix and uterus; (vi) parietal and pulmonary pleura; (vii) lining of the abdominal and pelvic cavities; (Viii) the surface of the organs contained within those cavities;
Dura and meninges; (ix) lesions involving any tumor in solid tissue that can be made accessible to light-activated light, directly, at the time of surgery, or by optical fibers inserted through a needle.

1-10% of incident red light (600-700nm) can pass through a 1cm thick human tissue slab, while blue light (about 400nm) can pass through only 0.001% or so through human tissue of the same thickness. As such, the wavelength of the photoactivation light is somewhat important. Thus, it would be more successful if the photosensitizer strongly absorbed red light. Pp IX strongly absorbs red light. This approach has several advantages over the prior art. First, Pp IX has a much shorter half-life than Hp IX, HpD or Photofrin II in normal tissues. This greatly reduces the risk of accidental phototoxic skin reactions after treatment. Second, the topical application of ALA to certain types of lesions will result in Pp IX within those lesions.
Can be induced, but not elsewhere. This improves the specificity of the treatment, reduces incidental phototoxic reactions to very low levels, and provides a uniformly effective dose of AL
Attempts to administer A systemically greatly reduce the amount of both ALA and Pp IX that would have been exposed systemically. AL
A and Pp IX are both common metabolites and are very easily processed by biochemical mechanisms in the body. However, because very high amounts of ALA (as well as high amounts of Hp IX or HpD) are associated with a temporary decrease in motor nerve conduction velocity, it is desirable to reduce the dose of ALA to the minimum amount that is still effective. Topical application is much less than systemic administration
Request ALA. Third, Pp IX is rapidly inactivated by photoactivation light. After exposure of the Pp IX-containing tissue to a therapeutic dose of photoactivating light, there is a substantial reduction in tissue photosensitization within the treatment volume. As a result, if Pp IX is induced by topical application of ALA to a particular lesion, the patient can be exposed to the sun immediately after treatment without the risk of serious phototoxicity. Fourth, when administered orally, topically or by injection, ALA is
It is an effective inducer of pIX. In contrast, Hp IX, HpD
And Photofrin II is most often effective only when administered by injection. This versatility of ALA increases the accessibility of physicians to everyday use. Oral and topical routes of administration are much more convenient than parenteral. Fifth, normal and abnormal tissues that can be sensitized by administration of ALA are somewhat different from those that can be sensitized by administration of Hp IX, HpD or Photofrin II. Thus, ALA may be useful in clinical situations where other photomodulators are not useful.

The technology of the present invention is in fact a significant advance in therapeutic capacity, as well as another way of doing what can already be done.

Example 1 An 87-year-old patient diagnosed with recurrent intraepithelial squamous cell carcinoma of the right cheek and mandible was treated with a 100 mg ALA dose per lesion in 17% (w / w) Glaxal base. Was treated by topical application of ALA. 2.5 hours after application, the lesions were treated with light-activated light, i.e. infrared (heat filter) and a wavelength below 600 nm (Hoya R-6).
0 filter) to the light output 500 watt tungsten lamp that has been filtered to remove, and exposed at a dose of 52.5mW at / cm ² (intensity × time). Patients were evaluated 40 days after treatment and the lesion was judged to be fully responding.

Example 2 A 73 year old patient diagnosed with squamous cell carcinoma in situ in the upper posterior and lateral right ear was treated with ALA in 10% (w / w) Glaxal base at a dose of 35 mg per lesion Was treated by topical application. 3 hours after application of ALA, lesions were obtained in Example 1.
At 26 mWh / cm ² from the light source described in Section ² . Evaluation 21 days after treatment showed a complete response.

Example 3 64 Diagnosed as having multiple squamous cell carcinoma at the following site:
Aged patient: (1) Back, left shoulder (2) Back, right rib cage (3) Dorsal, lower right rib cage (4) Left dorsal side, near fingers (5) Left dorsal side, center (6) Left hand, mother Lesions 1, 2 and 3 near the finger joints (approximately 10 mm bumps) were treated with 20 mg ALA per lesion in a 20% w / w Glaxal base. After 3 hours, it was exposed to light activation light from a light source described in Example 1 at a dose of 50mW at / cm ^2. Ten days after treatment, lesion 1 had a nearly complete response, lesion 2 had a partial response, and lesion 3 had a complete response. Lesions 1 and 2 and lesions 4, 5 and 6 were then treated with 22 mg ALA in 10% w / w Glaxal base for 3 hours and the following doses: lesion 1-17 mW h / cm ² lesion 2-17 mW in time / cm ² lesion 4-26mW at / cm ² lesion 5-26mW at / cm ² lesion 6-26mW at / cm ^2, it was exposed to the above-described light-activated light. Twenty-five days post-treatment, patients were evaluated as follows: Lesion 1-Complete response Lesion 2-Complete response Lesion 4-No recurrence Lesion 5-Partial response

Example 4 A 43 year old patient was diagnosed as having (1) dorsal, left shoulder and (2) dorsal, high lumbar vertebral area, right basal cell carcinoma and the patient was diagnosed with 33% w / w Glaxal Treated with 50 mg of ALA for 3 hours. Next, at 37 mW / c from the light source described in Example 1.
Lesions were photoactivated in m ^2. Evaluation 64 days after treatment showed complete response of both lesions.

Example 5 ALA was dissolved in an isotonic salt solution and then administered systemically to mice at a dose of 100-500 mg / kg body weight, either by subcutaneous or intraperitoneal injection. Three hours later, the mice were sacrificed and cryosections of the uterus were taken. Examination of the sections by fluorescence microscopy showed that the endometrium showed strong protoporphyrin fluorescence but did not show the underlying myometrium. Since ALA was administered systemically, it must certainly have been present in the myometrium and the subsequent loss of protoporphyrin fluorescence in the myometrium was due to the supply of excess exogenous ALA. I must show that. Thus, if ALA is applied directly to the surface of the endometrium, the myometrium will not become photosensitizing, and subsequent exposure of the endometrium and myometrium to light-activated light will Will result in preferential resection of membrane tissue.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication A61N 5/06 A61N 5/06 E (72) Inventor Raid, Robert El. Canada, Ontario K7 El 4 buoy 1, Kingston, Earl. R. # 1, Concord 5 (56) Reference Br. J. Cancer, Vol. 56 No. 5 (1987) p. 589-595 Cancer lett. (Shan non, Irel.), Vol. 36 No. 1 (1987) p. 1-10

Claims (5)

(57) [Claims] 1. A photochemotherapeutic or diagnostic composition for use in a patient in vivo in the detection or treatment of rapidly growing tissue that selectively accumulates protoporphyrin IX from its metabolic precursors. , The rapidly growing organization
Is selected from the group consisting of malignant and non-malignant abnormalities or lesions of the skin, conjunctiva, mucous membrane, endometrium and urothelium, wherein the composition is photochemically effective therapeutically or in the tissue of the patient. A diagnostic amount of said protoporphyrin IX
An effective amount of said protoporphyrin for bioaccumulation
A composition comprising the precursor of IX. 2. The composition of claim 1, wherein said composition is administered to said patient prior to exposing said patient's tissue to light-activated light. 3. The composition according to claim 2, wherein said photoactivating light is in the range of 350-635 nanometers. 4. The method according to claim 1, wherein said rapidly growing tissue from said patient to be treated in vivo is a mucosa of the respiratory tract, digestive organs or cavities, mouth, pharynx, esophagus, stomach, intestines, intestinal appendages, rectum, anus. Duct, nasal passage, nasal cavity, nasopharynx, trachea, bronchi, bronchiole, ureter, bladder, urethra, vagina, cervix, uterus, parietal or pulmonary pleura, lining of peritoneal and pelvic cavities, and their cavities The composition according to claim 1, wherein the composition is selected from malignant or benign abnormalities or lesions of the surface of the organs contained within the dura, dura and meninges. 5. The method according to claim 1, wherein the precursor of protoporphyrin IX is 5-
The composition according to any one of claims 1 to 4, wherein the composition is aminolevulinic acid.